Real-Time Monitoring of Miniaturized Thermal Food Processing by Advanced Mass Spectrometric Techniques

Abstract

Mass spectrometry is a popular and powerful analytical tool to study the effects of food processing. Industrial sampling, real-life sampling, or challenging academic research on process-related volatile and aerosol research often demand flexible, time-sensitive data acquisition by state-of-the-art mass analyzers. Here, we show a laboratory-scaled, miniaturized, and highly controllable setup for the online monitoring of aerosols and volatiles from thermal food processing based on dielectric barrier discharge ionization (DBDI) mass spectrometry (MS). We demonstrate the opportunities offered by the setup from a foodomics perspective to study emissions from the thermal processing of wheat bread rolls at 210 °C by Fourier transformation ion cyclotron resonance MS. As DBDI is an emerging technology, we compared its ionization selectivity to established atmospheric pressure ionization tools: we found DBDI preferably ionizes saturated, nitrogenous compounds. We likewise identified a sustainable overlap in the selectivity of detected analytes with APCI and electrospray ionization (ESI). Further, we dynamically recorded chemical fingerprints throughout the thermal process. Unsupervised classification of temporal response patterns was used to describe the dynamic nature of the reaction system. Compared to established tools for real-time MS, our setup permits one to monitor chemical changes during thermal food processing at ultrahigh resolution, establishing an advanced perspective for real-time mass spectrometric analysis of food processing.

DBDIpy: a Python library for processing of untargeted datasets from real-time plasma ionization mass spectrometry

“…To showcase the utility of DBDIpy, we performed a demonstrational data analysis. The demo data are from a foodomics study where wheat bread was roasted and thermal reaction products were monitored by DBDI-MS ( Weidner et al , 2023 ). It consists of 4196 features.…”

Microbial metabolomics’ latest SICRIT: Soft ionization by Chemical Reaction in-Transfer mass spectrometry

“…Recently, SICRIT has been used to characterize compounds in real-time breath samples, murine brain tissue, yak milk, and car exhaust, to name a few. [7][8][9][10] The results of these studies show that the SICRIT source has the ability to ionize volatile compounds and favors smaller, less polar metabolites, slightly overlapping with electron ionization (EI) (Figure S2). Overall, these studies have demonstrated SICRIT's ability to differentially ionize volatile and nonpolar compounds, and we sought to test whether this source could ionize differential microbial metabolites compared to ESI based ionization of the same extracts.…”